Add experimental print setting action. The command is of the form:
print account_name listing.index_style
account_name is currently ignored.
The path, e.g. listing.index_style is split by "." and fed to
DotAddressable lookup trait method. The method checks the first segment
in the path if it matches any of the struct's fields, and then calls the
field's lookup method.
conf_override! wraps struct definitions and defines a secondary Override
struct that wraps each field in an Option. The macro mailbox_settings!
is used to select settings from an account & mailbox index. If a user defines an overriding setting, the macro returns the override instead of the immediately next in the hierarchy setting.
The selection is done for a specific field as follows:
if per-folder override is defined, return per-folder override
else if per-account override is defined, return per-account override
else return global setting field value.
Merge ui crate with root crate.
In preparation for uploading `meli` as a separate crate on crates.io.
Workspace crates will need to be published as well and having a separate
`ui` crate and binary perhaps doesn't make sense anymore.
Manos Pitsidianakis